The invention relates to radiation-shielding containers, and more particularly to containers for radioactive pharmaceuticals.
Radiation-shielding containers or xe2x80x9cpigsxe2x80x9d are well known in the medical industry for transporting and storing radioactive substances, particularly radioactive drugs known as radiopharmaceuticals. Many prior art containers utilize a hollow, jar-like body with a lid. In order for these containers to effectively shield the radiation emitted by the radiopharmaceutical in the container there must be a tight seal between the radiation-shielding material of the body and the lid.
Prior art containers have provided tightly sealed components in a variety of ways. Some containers utilize a construction having a two-piece container with smooth mating surfaces that can be clamped together, thereby forming a seal. Each piece is typically made from a high-density radiation-shielding material such as lead or tungsten.
Other prior art containers have attempted to provide a means for securing the lid directly to the body using well-known methods such as engageable threads or snap fits. This configuration offers the advantage of simplicity and overcomes the requirement of additional structure to seal the container.
Radiation shielding materials, particularly lead, are generally extremely ductile and offer limited durability when machined or formed to provide threaded engagement. Known container assemblies relying on clamping apparatus entail the disadvantageous aspect of requiring additional structure to secure multiple container components together, such as a removable plastic housing or a series of clamps. This additional structure adds undesirable complication and cost to the container and can be difficult to assemble and disassemble. As such, a radiation-shielding container that is inexpensive, durable, easy to use, and that may be fabricated entirely of high-density radiation-shielding material, would be welcomed by those in the industry.
Accordingly, in one embodiment the present invention provides a radiation-shielding container for a radiopharmaceutical. The container includes a generally cylindrical base that is formed of a radiation-shielding material and includes an inner surface defining a cavity and a central axis. The cavity includes an open end and a closed end, and the base defines at least one helically extending groove that is radially outwardly recessed with respect to the inner surface and extends generally inwardly from the open end. The container also includes a generally cylindrical cap that is formed of a radiation-shielding material and includes a generally annular protrusion that is received by the cavity. The cap also includes at least one tab that extends radially outwardly from the annular protrusion and is engageable with the at least one recess to secure the cap to the base, thereby closing the cavity.
In another embodiment, the present invention also provides a container for radioactive substances that includes a base having an interior wall defining an open end, a cavity, a central axis, and a recess extending axially inwardly from the open end. The recess includes a lower engagement surface that faces the open end and extends between a first edge that is adjacent the open end to a second edge that is circumferentially and axially inwardly spaced from the first edge. The recess also includes a stop surface adjacent the second edge, and an upper engagement surface facing the lower engagement surface and extending from the stop surface toward the open end. The container also includes a cap having a cross-sectionally reduced portion that is receivable by the open end of the base to extend into the cavity. The reduced portion includes a radially outwardly extending tab that is receivable by the recess and is engageable with the lower engagement surface. The container is configured such that rotation of the cap with respect to the base about the axis slides the tab along the lower engagement surface and into abutment with the stop surface and the upper engagement surface, thereby securing the cap to the base.
Other features of the invention will become apparent to those skilled in the art upon review of the following detailed description, claims, and drawings.